So sorry to read your post.

This I think falls into the realm of 'Catastophic Thinking'. I have both social and generalized anxiety and really fret about what other people think of me; not just am I making a fool of myself, but am I annoying or pissing off those around me. And yes, leaping to worst case scenarios is part and parcel with this. So too is low self-worth. Could this be part of the case? You've mentioned the bullying which is a classic contributor to this sort of thinking.

So, what can you do. Well, therapy can help. Personally I found Cognative Behavior Therapy (CBT) to be beneficial. It taught me a number of coping skills; in particular, de-constructing catastrophic thinking.